Hi I'm new to this site. Looking for some help. My father has been diagnosed with nodular malignant melanoma and is currently awaiting a wide excision and possible snb. I have been trying to gain some info so that we know what to expect and have seen letters sent by the hospital to his gp which said after the first biopsy it had a depth of 4mm or more the second letter after another procedure says that it is 2.5 cm (25mm)depth. Is this right? Please help I'm going out of my mind